Lost file associations when disconnecting/reconnecting external hard drive

Question

Dear iTunes pros,
I have a question that I haven't been able to find an answer to despite searching various forums.
I used to have all my music in the iTunes Music folder on my local drive. But some time ago I added to the iTunes library a lot of music that I had on my external hard drive - importantly, when adding it, I did not choose the consolidate library option as 1) I don't have enough space on C:\ to move all that music from the external hard drive to the iTunes Music folder on C: 2) for that particular collection I wanted to keep my original folder structure and not have it rearranged by iTunes according to the standard artist/album/file format.
Everything was well until I disconnected the external drive and reconnected it again. Now iTunes cannot play any of the files that I have on the external drive -- I get an exclamation point next to each one saying that the original file cannot be found.
This would be normal if I tried to play these files with the hard drive disconnected -- obviously then iTunes cannot locate the files as they are not there on the system.
But once I have reconnected the external hard drive, shouldn't the cross-references in the iTunes library files work correctly again? I have not changed anything with the files, the paths remain correct, so why can't iTunes see the files? (Let me add that there is nothing wrong with the hard drive -- I can easily play the files with other players - or even with iTunes! - if I simply go to their location on the external drive and double-click on them)
How do I get my file associations back? Let me add that I don't want to consolidate my library at this moment.
I hope there is an easy way to do this as obviously manually reconnecting several thousand library entries to files is not an option.
I will be immensely grateful for any ideas.

Answer 1

My guess is that the drive letter to your external drive has changed. This can happen with Windows if you don't affix it to a specific letter permanently. Try this:
1- Check to see what letter Windows currently has assigned to your external drive. Next you need to check to see what iTunes thinks the letter should be. If you know that the drive letter changed and remember what it was, skip step #2 & 3.
2- Locate your "iTunes Library.xml" file and make a copy. Open the copy with Excel if you have it, Internet Explorer can also open it.
3- Look for an entry like "file://localhost/E:/My%20Music ..." In this example iTunes knows my files are on my E:/ drive. Close the copy of the .xml file.
4- If iTunes and Windows are reporting different letters then you need to tell Windows what the letter should be. Go to Windows Disk Management and assign the letter that iTunes last used for the drive. I believe there is an option to make the letter permanent.
5- Open iTunes and you should be good to go.